Dependence of the agrotech-nical clearance under the front axle of a cotton tractor with a wheel arrangement 4K4a on the dimensions of the pivot pin, the size of the tires of the steered wheels and the angles of their installation

At present, the concept of the transition of cotton energy to a four-wheeled power plant is being worked out in the republic. And it has, in comparison with the existing one, an additional potential for increasing productivity due to increasing the ranks of agricultural machinery. Cotton refers to high-growth technical crops, as at the stage of maximum biological development plants reach a height of 800...1250 mm. Minimal traumatization of the above-ground part of the plants during the processing of row spacing and loss of harvest during harvesting is largely due to the increased agrotechnical clearance of cotton-growing tractors. The modern cotton tractor has a scheme of propulsors with axle configuration of 3K2 and clearance of 820...830 mm under tubes of shafts of rear axles, due to the installation of additional final gears. The front steer axle is single-wheeled, it does not prevent the safe passage of plants under the tractor's framework. When developing a four-wheeled cotton tractor, a major problem is the provision of the required agro-technical clearance under the tube of the front axle. Preliminary studies have established that it is possible to change the agrotechnical clearance under the portal structure of the front axle by changing the length of the pivots of the pivot pins to the dimensions that provide the four-wheeled tractor with satisfactory flotation above the row of cotton. At the same time, it is necessary to take into account the known effect of the linear and angular dimensions of the front axle on the kinematic characteristics of the steering and the operation of the propulsors, in connection with which the analytical interrelation of the agrotechnical clearance under the front axle of the tractor with axle configuration 4K4a, the dimensions of the pivots of pivot pins, the dimensions of the steered wheels and the angles of their settings, allowing to calculate the amount of agrotechnical clearance under the beam of the front axle for different combinations of arguments that are included in this dependence. For example, it is established that with the length of the pivot shaft of the experimental front driving axle of 435 mm and the installation of 11.2-20, 11.2R20 and 11.2R24 tires, an agro technical clearance is provided within 826...877 mm, which meets the requirements of the technical specification for the cotton tractor.